Yamaha's Seamless Gearbox Tested At Brno: A 143% Improvement Over The Conventional Gearbox

It had been widely rumored that Yamaha would have some important updates to test at their private test being held yesterday and today at Brno. The biggest expected update to be tested was a seamless gearbox, but though Yamaha Racing Managing Director Lin Jarvis had hinted they might be testing the new gearbox, it was far from certain. As the test at Brno was a private one, no media were invited who would be able to verify whether the seamless gearbox was being tested or not.

Fortunately, however, the Brno circuit was allowing visits in to watch the test. And among those was Pavel, who runs the Czech Valentino Rossi fansite http://www.rossi-yamaha.cz/. Pavel shot some video footage of the private test - thankfully not covered by the blanket ban Dorna has on all coverage of the official tests - and was kind enough to send us the audio from the recordings. Armed with that audio, we were able to analyze the sound, as we have done previously (on both the Honda and the Yamaha), to try to judge whether Yamaha were indeed testing a seamless gearbox, and if they were, what advantage it was giving them.

The answer to the first question is yes they are. Or at least, that is the picture which emerges from the data. Looking at the length of time the bike goes quiet, at the point when the gearchange happens, it is clear that the gearchanges are much faster. Taking a random sample of clearly audible gearchanges, and measuring the duration the engine is quieter (see the image for an example), we can see that shift times are improved. Assessing the times, gear changes now appear to be taking approximately 0.016 seconds - sixteen thousandths of a second - per shift, rather than the 0.038 found from previous measurements. That is an improvement of over 0.02 seconds, or 143%. Yamaha's seamless shift is still not as quick as Honda's: from measurements made at Jerez, the Honda RC213V was taking just 0.009 seconds to shift between gears, an incredibly short period of time. The Honda is still changing gear in just 56% of the time which Yamaha's new seamless gearbox takes.

However, that may not be that much of a disadvantage for Yamaha. The real benefit of a seamless gearbox is not so much the shortened shift time - though clearly, that helps - as the extra stability the shorter shift brings to the bike. The difference is clearly visible from track side: the Honda stays smooth as the riders shift up the gears, even when still leaned over. The Yamaha's rear gives a little wobble, as the power is disengaged and then reapplied. The hope is that Yamaha's new seamless gearbox will give the M1 the Honda's stability, allowing the Yamaha riders to accelerate harder and earlier. This would improve the one weakness the Yamaha M1 still has compared to the Honda, and give Jorge Lorenzo and Valentino Rossi a better chance of beating the factory Hondas of Dani Pedrosa and Marc Marquez once it is introduced.

When that will be is still unknown. Although the gearbox has undergone extensive reliability testing in Japan, whether the gearbox is race ready remains to be seen. In a second video, Valentino Rossi was shown having run off the track, and struggling to get the bike back into a usable gear. The engine was still running (just audible in the video), but Rossi's attempts to get the bike moving again appear to fail, and he has to wait for a Yamaha technician to help push him off the track. Reports from the track were that the bike made a horrible noise as Rossi was downshifting, just before he ran off track, and that would appear to suggest that the gearbox may have been a problem.

Then there is the question of whether the new seamless gearbox can be retrofitted onto Yamaha's existing engines. That is up for debate, but early reports suggesting Yamaha was already using the seamless gearbox may be the result of new gearbox casings being used, which have been redesigned to house both the seamless and the conventional transmissions. Once the gearbox is in use, and when the engine allocation charts show both a new engine and an old engine being used, we will be able to analyze the sound once again, and see which bike is using which gearbox.

Measured times:

Audio time Gear change length (seconds)
3:07.340 0.014
3:05.729 0.016
3:42.100 0.017
4:00.971 0.016
4:02.634 0.016
4:07.313 0.015
4:27.141 0.017
4:25.368 0.014
Average 0.016

Comparison with Yamaha's conventional gearbox:

Gearbox Yamaha
Time 0.016 0.038 0.009
% compared to
Yamaha's seamless
  243% 56%

Times are approximate, as the audio for the Yamaha seamless, and Honda and conventional Yamaha gear changes were recorded on different devices. Though the audio should be the same, very small differences may occur. That means the audio could be out by a very small margin, but those differences will be less than 0.001 of a second. Times are all rounded down to 0.001, meaning the percentages are slightly different due to rounding effects.

Yamaha testing, Day 1

Yamaha testing, Day 2

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Good to see Yamaha is making an effort! The ability to shift while leaned over should allow more flexible and/or optimal gearing. This may produce fuel savings, or even improve drive in the higher gears, when the bike is not wheelie-limited.

Since posting this, I've been engaged in various debates over how much of an improvement the Yamaha gearbox is. Clearly, my math is fairly poor, but I was trying to convey just what a leap forward it is. I need to revisit the best way to communicate this, and try and get it mathematically correct.

For example, 0.016 is less than half the duration of 0.038. Which means that something which takes 0.016 seconds is over twice as fast as something which takes 0.038 seconds. Despite only being a 57% improvement...

I think what people are struggling with is that you chose the middle value to compare against which means that mathematically you have compared the values in opposite directions which makes the resulting percentages look awkward when comparing the 3. for example if you choose the Yamaha non seamless as the base point you end up with

non seamless yam: 0.038 100% base

seamless yam: 0.016 237.5% faster than non seamless

seamless Honda: 0.009 422% faster than non seamless yam, 177% faster than seamless yam

or in the other direction

non seamless yam: 0.038 100% base

seamless yam: 0.016 42% of the time of the non seamless

seamless Honda: 0.009 24% of the time of the non seamless yam, 56% of the time of the seamless yam

great technical analysis David

The new Yamaha shift speed is 2.4 times faster than the non-seamless shift
The current Honda shift speed is 4.2 times faster than the current Yamaha shift speed
The current Honda shift speed is 1.7 times faster than the new seamless Yamaha shift

You are in fact missing something.
Percentages are just multiplication factors that describe how one number corelates to another number, multiplied by 100 and added with the % sign.

The reference time here is in fact 0.016, not 0.038, so a percentage of 243 means that you have to multiply 0.016 by 2.43 in order to get 0.038.

I'm not sure how you have gotten the 57.8%, since 0.016 is 42,10% of 0.038.

Sometimes people tell me that my clinical style of writing seems condescending, I asure you it is not, we all makes mistakes, especially me, you should see my math notebook..I use the eraser a lot...

Lorenzo on a smoother Yamaha? That sounds troubling for Honda.

And let's not forget how inapplicable to production bikes this sort of gearbox rules workaround is. Why would they consider something so complex and fragile (or at least that's my impression) when dual-clutch is so much simpler and should be quite reliable.

For crying out loud, Honda already *has* a production dual-clutch motorcycle transmission, even if it isn't on a pure sportbike...

... but if you really want to spend your competitors out of the sport, the last thing you want is them being able to actually sell in showrooms the technology developed in their racing depts. That could even help them support their racing effort. It is obviously better to force them spend whatever they want for their road-going bikes' development, then have them spending significantly more for race-only technology ... And in all this spending war, guess who would be the last man standing ...

Yes, it's pretty stupid now that you point it out.

I take it that this rule was brought in at a time when only Honda had the resources to implement a dual clutch set up?

Unintended consequences, the dictionary definition thereof. And this is exactly the danger of trying to outlaw certain types of technologies. We try to "fix" the immediate problem, only to create a much larger headache two years later.

Sure the technology is great for racing and lowering lap times but, 98% of sport riders who buy production bikes from the dealer...enjoy shifting. Of all the high cost things on the list to be banned, this should but top.

Cruiser, tourers and scooter riders are likely chomping at the bits to see this seemless transmission techology flurish, but as great of an idea it is, for the price I would shelve it until the series became more healthy and stable. MM. Lorenzo and the like do not need this to beat the other nonfactory teams. This just opens the gap further. Why is that a good thing?

It's not that I can't appreciate it. Just do see the need at this stage.

Honda's system (which clearly works fantastically on the track) won't work on the street. From David's interview of Mr. Nakamoto 2 years ago:

Q: Is the gearbox, the transmission technology, is that something that could come to road bikes one day?

A: "I don't think so. Because racing machine transmission, usually shift up is at maximum revs. If you short shift, in this case a big shock happen with the new transmission system. But a road bike usually short shifts, and never uses maximum revs. But on the road, is very very few times."

Again, terrific insight here David
Being a Rossi fan, I'm always happy to see him get improvements.
As for production application, rekluse clutch is gaining a lot of popularity in the off road world so perhaps some 'cheaper' version of this seamless gearbox would be seen in that arena?
That said, judging by the clip Mr. Rossi didn't seem to find it much use when off road...

Roll on Indy

As ever David, thanks for this. I still don't quite understand just why it's taken Yamaha so long to develop this gearbox. I know, I know, they keep pleading poverty. But SURELY a company the size of Yamaha can see the validity of this. After all, winning on Sunday means selling bikes on Monday (apparently).

Jorge and Valentino have been wanting this since HRC introduced the DC system (what, 3 years ago now)??? I remember Jorge calling for it whilst Valentino was at Yamaha last time!. Just seems a little strange to me.

didnt sound so seamless to me? still could hear some back fires i thought! but at my age my hearing isnt so good.

if you want to improve something, the improvement is based on where you started. yamaha shifting baseline is 0.038 seconds with the current gearbox, the improved shifting duration is 0.016 seconds with the seamless gearbox. that change from A to B is a 57.8% improvement. full stop.

i have no idea where 143% even comes from, it has no basis in logic or mathematical principles or common sense -- iand 'm assuming we're shooting for some semblance of journalistic integrity here.

otherwise, great reportage and website btw!

Maybe the unit used isn't appropriate, instead of duration it should be frequency or speed.

Let me give you a an example. Say an engine is tuned from doing 6000 revs (per minute) to 12000. Clearly a doubling, or 100% improvement.

Now look at the time a single rev takes: 1 / 6000 / 60 = 0.010 seconds. After tuning: 1 / 12000 / 60 = 0.005 seconds. According to your argumentation, that would only be a 50% improvement. Wrong, because you looked at the duration.

When looking at something which can be improved by increasing it (bhp, revs, etc.), your way of determining percentages is correct. However, when the goal of the improvement is in reducing duration, you need to reverse that direction. Which equals to looking at the newly achieved speed or frequency.

Very well put. I totally agree. I think David will find here the words he was looking for to explain his point.

However, as discussed here some time ago the need for this particular technology is driven purely by the need to get around the rules.
I would be very interested to understand how this shifting works - if the transfer between one gear train and another is 'mechanical' or electro-mechanical for example. Do hydraulics play a part? The secrecy around HRC/Yamaha's particular solutions may make that unlikely but perhaps they would be willing to tell us where their solution is different, if nothing else?

It must take a pretty dumb rule-maker to write/accept a rule that only prohibits one type of 'auto' though, when someone would (already had?) developed a work-around. Perhaps HRC already had the answer when the rule was agreed....

Ducati seem to have developed theirs in fairly short order after HRC, and I wonder if their are any similarities between the Ducati and Yamaha solutions (i.e. did Burgess or others glean anything)?

Also - is the F1 solution the much simpler/cheaper/reliable dual clutch or do they use a similar method to MGP?

Whatever their solution I do hope that Yamaha can successfully use it in a race this year, given the advantage HRC seem to have gained.

Then, please ban it as it is clear that the CRT's/non-factory teams can no more afford this than they can pay for a full production racer, a top tyre contract, or employ test teams, and it is technology for the sake of it. Why Dorna has taken so long to react is puzzling.

Check out UK's Zeroshift, they produce seamless gearboxes. There's video and diagrams on their site, showing how the system works. Very cool stuff.

Less expensive to manufacture (per unit) says nothing about development cost behind the product.

People saying "HONDA'S GEARBOX" BUT.....first thing is Yamaha develop the seamsless gearbox in house.! Honda didn't develop the seamless gearbox, Honda just bought the gearbox from an english company who designed those gearboxes for years now in several sports! So its more easy and it dont take like with Yamaha several year to develop a new gearbox that has to be working faultless.

Thanks for the pointer.
This changes my view to some degree. It actually looks a relatively simple technology and is marketed as an affordable and improved type of auto (even over DC systems).
It seems that perhaps HRC and others have some form of licensing agreement with the Z boys - to develop and fine-tune the performance. Honda's shift time may be a sign/result of this. The comment above about Nakamoto suggesting it wasn't any good for slower changes may be true , or a smokescreen.
This could, perhaps, be the difference between the shift performance on different types of bike - a slower shift would be 'softer' and allow fuel/ignition management to unload the gear train to some degree to reduce wear rates and shock loads. Like a quick-shift, the full-throttle, fast as possible, race shifts would give the gearbox a harder time unless the speeds, gearing, and power characteristics are well-matched.
It seems that this is road-tech being adapted to high-performance and not the reverse. However, if the R&D produces better outcomes for road applications then this is still a good effort and I no longer see it as a waste of money.

I personally think its a huge & good step forward by the yam factory team, i agree with YZRM1(user) that buying a gearbox and working around it is different rather than developing their own. Whatever the reason now, Being a huge VALE fan i'm happy for him and the team. Lets see how well it works when doing a 'RACE'

And no matter what mathematics is going on top here, the end result is that it is an improvement and it is working well with the Baby M1 (46) & (99) ;D :D

Hoping soon that they introduce it to the Races and we have a faring to faring race when it comes to acceleration and corner entry with the Honda's. Might be a good battle with all our lovely aliens, 46, 93, 99, 26 & Maybe 35 too(If they Give him the Seamless box ;) b4 he waves good bye to tech3) Man what a treat it is going to be to our eyes, M getting goose b**S now :D

Go! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! !

Really looking 4ward to it.